6beta-Hydroxy-hydromorphone is a metabolite of hydromorphone. Hydromorphone, a more common synonym for dihydromorphinone, commonly a hydrochloride (brand names Palladone, Dilaudid, and numerous others) is a very potent centrally acting analgesic drug of the opioid class. It is a derivative of morphine, to be specific, a hydrogenated ketone thereof and, therefore, a semi-synthetic drug. It is, in medical terms, an opioid analgesic and, in legal terms, a narcotic. (Wikipedia)

This compound belongs to the class of chemical entities known as morphinans. These are polycyclic compounds with a four-ring skeleton with three condensed six-member rings forming a partially hydrogenated phenanthrene moiety, one of which is aromatic while the two others are alicyclic.